Safety arrangement for automatic warehousing facility

ABSTRACT

A safety arrangement for an automatic warehousing facility is disclosed. A traveling crane adapted to perform goods take-in and take-out operations is provided which is movable on a path provided between and extending along a plurality of three-dimensional racks arranged in parallel for storage of goods. There is provided a safety arrangement for safeguarding any operator from possible danger when he inadvertently enters the path of crane movement while the crane is in automatic operation, and for preventing the crane from moving when the operator is present within the path of crane movement. The safety arrangement includes a device for stopping the crane when an open/close door of a safety enclosure provided at one end of the crane movement path is opened.

FIELD OF THE INVENTION

The present invention relates to a safety arrangement for an automaticwarehousing facility.

BACKGROUND OF THE INVENTION

Automatic warehousing facilities are well known which are of the typehaving a plurality of three-dimensional racks arranged in parallel, atravel path provided between each two adjacent racks and extending alongthe racks, a traveling crane movably mounted on each travel path tocarry out goods take-in and take-out operations, and a station locatedat one end of each travel path for handling incoming and outgoing goods.In such an automatic warehousing facility, it is required that formaintenance and inspection purposes, or in case of emergency, anoperator must enter the travel path of the crane. This poses a serioussafety problem. There may be a danger of injury or death if the operatorshould carelessly step into the travel path when the crane is inautomatic operation, or if the crane should start moving on account ofmisoperation or otherwise when the operator is present in the travelpath. Moreover, in the above mentioned known automatic warehousingfacility, it is necessary to provide a control board for controlling thecrane. In the known automatic warehousing facility, the control board islocated independently, apart from other equipment, so that not only isthere cost for this control board per se but also additional cost forindependently locating this control board. Therefore, the total cost forthe known warehouse facility is high.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the invention to provide a safetyarrangement for an automatic warehousing facility which eliminates theabove mentioned problem.

In order to accomplish this object, according to a first aspect of theinvention there is provided a safety arrangement for an automaticwarehousing facility equipped with a traveling crane adapted to carryout goods take-in and take-out operations and movable along storageracks, comprising:

a crane travel path extending along the racks,

a safety enclosure provided with an open/close door which is disposed atone end of the travel path,

discriminator means which determines whether or not the open/close doorof the safety enclosure is in closed condition,

control means which prohibits the crane from moving when thediscriminator means has detected the open/close door is not in theclosed condition,

wherein said safety enclosure further comprises safety fence meansdisposed on both sides of the crane travel path and a crane controlboard, and

wherein said open/close door and crane control board are placed in a rowin front of the said one end of the travel path, connecting with saidsafety fence means on both sides of the path in U-shaped fashion.

According to such arrangement, the crane is enabled to move only whenthe open/close door of the safety enclosure is in closed condition.Therefore, if the operator should open the open/close door accidentallyto enter the travel path when the crane is in motion or when thewarehousing facility is in an automatic operation mode in which thecrane is likely to start moving automatically, the discriminator meansdetects the opening of the door, whereupon the control means operates todisable the crane from moving. Thus, possible danger of contact orcollision of the person entering the travel path with the crane inmotion can be prevented. The safety enclosure comprises fence means, theopen/close door and the control board, so that the control boardconstitutes a part of the safety enclosure. Because of this, the controlboard is connected to the components of the safety enclosure such asfence means, increasing its set up strength. As a result, unlike thecase where the control board is independently located, no reinforcedlegs supporting the control board or means to securely fix the controlboard to the floor are needed. Moreover, shortening of the total lengthof the fence means partly contributes to a great reduction in the totalcost for the facility. Furthermore, it becomes unnecessary toindependently locate the control board onto the floor surrounding theend of the crane travel path, which is used, for example, as atravelling path for incoming and outgoing goods-receiving trucks orforklift trucks. Consequently, it becomes possible to make the mostefficient use of the floor surrounding the end of the crane travel pathand to insure safety there.

According to a second aspect of the invention, there is provided asafety arrangement comprising:

a control panel of a portable size which is to be handled by a craneoperator for operating the crane at a suitable distance therefrom,

said control panel being removably installed on the crane at a positionsuitable for direct access of the crane operator at a ground site,

said control panel having an interlock release switch located at aposition that is accessible only when the control panel is removed fromthe crane, and

said control panel being inoperative to move the crane unless aninterlock is released by the interlock release switch.

According to such arrangement, operation can be carried out while thecontrol panel is mounted in position on the crane. This affords greateroperating efficiency as compared with the case in which the controlpanel has to be carried in hand all the time during operation. The cranecannot be moved when the control panel is present on the crane and,needless to say, this assures good safety. When it is necessary to movethe crane, the control panel should necessarily be removed from thecrane and carried in hand, and yet the crane operator can positionhimself at a safe distance from the crane. Therefore, the crane operatorcan carry out operations under very safe conditions for moving the cranewhile walking after the crane with a reasonable distance kept therefrom.

The invention, in its third aspect, provides a safety arrangementcomprising:

a control panel for manually operating the crane which is disposed atone end of the crane as viewed in the direction of movement of thecrane,

first and second operating switches disposed respectively on saidcontrol board and at the other end of the crane as viewed in thedirection of movement of the crane, and

means for disabling said crane from at least its moving when one of saidoperating switches is manipulated.

According to such arrangement, any operator who has entered the travelpath of the crane can easily perform a safety operation for disablingthe crane from movement. Inasmuch as the crane is disabled from movementby the second operating switch which is located opposite to thecrane-operating control panel, there is no danger of the control panelbeing operated by another operator to move the crane; and thereforeoperation can be carried out in safety within the crane travel path atthe opposite side of the location at which the control board isdisposed.

The invention, in its fourth aspect, provides a safety arrangementcomprising:

a vertically movable carriage having transfer means,

a crane support for guiding the vertically movable carriage,

a ladder provided on the crane support and having a pair of laddersupports,

a guide rail formed integrally with at least one of the ladder supportsand projecting from the ladder support over its entire length, and

a safety rope connecting slider up and down movably held in engagementwith said guide rail and having a safety rope connected thereto, wherebysaid slider is automatically locked in position when the safety rope ispulled downward.

According to such arrangement, because of the fact that the guide railfor guiding the slider is integral with at least one of the laddersupports, no particular work is necessary for mounting the guide rail tothe ladder. This eliminates the danger of disconnection of the guiderail from the ladder. The one ladder support and the guide rail, incombination, form a highly rugged structure which affords greater safetywhile providing for reduction in size and weight of the entirety of theladder with safety attachments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an automatic warehousing facilityequipped with a safety arrangement representing one embodiment of thepresent invention;

FIG. 2 is a front view of a safety enclosure shown in FIG. 1;

FIG. 3 is a perspective view showing a principal part of the safetyarrangement together with a relevant control circuit;

FIG. 4 is a side view showing a crane equipped with a safety arrangementrepresenting another embodiment of the invention, as seen when it ismanually operated, with a control panel set in position on the craneside;

FIG. 5 is a fragmentary side view showing the crane being manuallyoperated by means of the control panel as drawn out from the crane;

FIG. 6 is a perspective view showing the control panel and a console inFIGS. 4 and 5;

FIG. 7 is a flow chart showing a control procedure with respect to thecontrol panel and console;

FIG. 8 is a plan view showing an automatic warehousing facility equippedwith a safety arrangement representing another embodiment of theinvention;

FIG. 9 is a side view showing a crane in the automatic warehousingfacility in FIG. 8;

FIG. 10 is a perspective view showing a control box in the safetyarrangement of the FIG. 8 embodiment;

FIG. 11 is a control circuit diagram with respect to the safetyarrangement of the embodiment;

FIG. 12 is a side view showing an operating crane in a furtherembodiment of the invention;

FIGS. 13 and 14 are, respectively, a front view and a plan view showingthe crane;

FIG. 15 is a transverse sectional view in plan showing an emergencyladder in the crane; and

FIG. 16 is a transverse sectional view in perspective showing a laddersupport in the ladder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 3 illustrate one embodiment of the invention.

In FIG. 1, numeral 1 designates a traveling crane assigned to carry outgoods take-in and take-out operations and movable on a travel path 4provided between adjacent parallel racks 2 and 3. The crane 1 is of theknown type having a vertically movable carriage 6 equipped with transfermeans 5, such as a retractable fork. Numerals 7, 8 designate incomingand outgoing goods receiving trucks arranged outside respective one endsof the racks 2, 3 and movable on guide rails 9, 10 between a deliveryposition A corresponding to a home position HP at one end of the travelpath 4 at which the crane 1 stops and another delivery position B spacedapart from the position A. Alternatively, a fixed type goods-receivingplatform may be provided at the delivery position A. Further, both ofthe incoming and outgoing goods-receiving trucks 7, 8 and the fixed typegoods-receiving platform may be provided only on one side of the travelpath, serving for both incoming and outgoing purposes in place of thetwo sided type arrangement shown in FIG. 1.

Numeral 11 designates a safety enclosure which encloses the homeposition HP side terminal of the travel path 4 in U-shape fashion. Thesafety enclosure 11 comprises a pair of safety fences 12 at sides, anopen/close door 13, and a stationary wall 14. Numeral 15 designates acrane control board mounted on the stationary wall 14, and numeral 16designates safety fences provided outside travel paths for incoming andoutgoing goods receiving trucks 7, 8.

As FIGS. 2 and 3 illustrate, the open/close door 13 is pivotallysupported by a pair of hinges 17 at the opposite side of the stationarywall 14 so as for it to be freely opened and closed, and is adapted tobe stopped at a closed position by a stopper plate 18 provided at thestationary wall 14 side. Numeral 19 designates an open/close leverrotatably supported at an outer side of the open/close door 13 which isinterlockingly connected through a rotational shaft 21 to a lock lever20 disposed at an inner side. Numeral 22 designates a lock lever lockingmember disposed at the stationary wall 14 side which is adapted to beengaged by the lock lever 20 for preventing the open/close door 13 whenthe open/close door 13 is in its closed position at which it is inabutment against the stopper plate 18 and when the lock lever 20 isrotated by the open/close lever 19 in the clockwise direction as viewedin front. Numeral 23 designates a limit switch such that normally opencontacts 23b are closed by a plunger 23a being kicked by the front endof the lock lever 20 which is in engagement with the locking member 22as above mentioned. The limit switch 23 is attached to the stationarywall 14.

The normally open contacts 23b of the limit switch 23 are connected inseries to an electromagnetic relay 24 operative to turn on and off powersupply to a drive circuit for the crane 1 and to a normally closedswitch 25 for emergency stop which is adapted to be opened throughemergency stop control, as shown in FIG. 3.

According to the above arrangement, the normally open contacts 23 of thelimit switch 23 are closed when the open/close door 13 is locked to itsclosed position by the lock lever 20. Accordingly, the power on-offelectromagnetic relay 24 is excited to connect the drive circuit for thetraveling crane 1 to the power supply. Therefore, it is possible toactuate the crane 1 to carry out goods take-in and take-out operationsby manipulating the crane control board 15. When the lock lever 20 isrotated counterclockwise as viewed frontways by means of the open/closelever 19 to become disengaged from the locking member 22 whereby to openthe open/close door 13, the plunger 23a of the limit switch 23 is movedaway from the front end of the lock lever 20 so that the normally opencontacts 23b of the limit switch 23 are allowed to open. As a result,the power on-off electromagnetic relay 24 is deenergized and the drivecircuit for the traveling crane 1 is disconnected from the power supply,in the same way as in the case where the normally closed switch 25 foremergency stop is opened to bring the traveling crane 1 to an emergencystop. Therefore, the traveling crane 1, if it is in operation, isautomatically stopped, and if not in operation, the traveling crane 1cannot be operated even if the control panel 15 is manipulated.

When the power on-off electromagnetic relay 24 is demagnetized, thetraveling crane 1 is disabled not only from moving, but also fromperforming all other functions including up-and-down movement of thevertically movable carriage 6 and operation of the transfer means 5,because the relay 24 is designed to disconnect, through demagnetizationof itself, the driving circuit for the traveling crane 1 from powersupply. However, it is possible to arrange that the traveling crane 1 isdisabled at least from moving when the normally open contacts 23b of thelimit switch 23 are opened.

It is also possible to utilize a proximity switch or a photoelectronicswitch for non-contact detection of the lock lever 20 in its lockingposition with respect to the locking member 22. In order to furtherimprove the safety at the time when the open/close door 13 is closedagain to put the traveling crane 1 in the travelable condition again,not only is the open/close door 13 closed and the lock lever 20 engagedto the locking member 22, but also the traveling crane 1 can be keptfrom the travelable condition unless a release switch on the controlpanel 15 is operated.

As FIG. 1 shows, the safety fences 12, 16 extend in the direction ofmovement of the crane 1. Therefore, any operator cannot enter the travelpath 4 sideways, it being only possible for him to enter through theopen/close door 13. Thus, any careless entry into the travel pass can beprevented. The stationary wall 14 and crane control board 15 constituteonly a part of the enclosure for the travel path 4. This provides aneconomical advantage as compared with the case in which the travel path4 is surrounded completely by an extensive safety fence, with the cranecontrol board 15 disposed separately from the fence. As FIG. 1 shows,the control board 15 is disposed inside the safety enclosure and adaptedto be manipulated outside the enclosure. Therefore, workers can, at alltimes, perform their jobs outside the safety fences. Also, safety fences16 are provided outside the travel paths for goods receiving trucks 7,8. This assures safety with respect to the trucks 7, 8 as well.

FIGS. 4 to 7 illustrate another embodiment of the invention.

In the automatic warehousing facility shown in FIGS. 1 to 3, the crane 1is operated by the control board 15 which is disposed on the groundside. There may be cases where a supplementary control panel is attachedto the crane itself to enable the operator to manually operate the crane1 in case of emergency or during the process of maintenance andinspection.

Such a control panel mounted on the crane 1, as is the case with themain control board 15 disposed on the ground side, has operating buttonsand the like for controlling the movement of the crane 1, up and downmovement of the vertically movable carriage, and movement of thetransfer means. In a small-type crane having no operator's cab, suchsupplementary control panel has to be disposed at such a position as isconvenient for direct control by the operator present on the groundside.

In such type of crane 1, which is to travel within a narrow space of thepath 4 defined between parallel racks 2, 3, the supplementary controlpanel is attached to one end of the crane 1, e.g., the rear end asviewed in the direction of movement thereof. Accordingly, the operatorwho is to manipulate the control panel should take his position at alocation within the travel path 4 and adjacent the rear end of crane 1.In such condition, it is very dangerous to move the crane 1 rearward,that is, toward the operator himself, even if the movement of the crane1 is limited to a low speed.

In view of this fact, the embodiment shown in FIGS. 4 to 7 is designedso that the crane cannot be actuated to run by the supplementary controlpanel at the crane side unless the condition of safety is assured.

The safety arrangement for an automatic warehousing facility accordingto the FIGS. 4 to 7 embodiment will now be described in detail.

In FIGS. 4 and 5, the traveling crane 1, assigned to carry out goodstake-in and take-out operations, comprises a lower frame 32 guided bylower guide rails 31 and an upper frame 34 guided by upper rails 33, thetwo frames 32, 34 being integrally connected to each other through apair of supports 35 spaced in the direction of movement of the crane 1,and a lift carriage 6 vertically movably supported between the pair ofsupports 35 and having a transfer means 5 disposed thereon. This type ofcrane is well known in the art.

Numeral 36 designates a control unit mounted on the lower frame 32 atthe rear end thereof which controls a drive unit 37 for moving the crane1, an up-and-down drive unit 38 for moving the lift carriage 6, and adrive unit (not shown) for moving the transfer means 5. The control unit36 has a console 39 which faces upward at an angle in the rearwarddirection.

The console 39 is formed with a recessed portion 41 in which isremovably received a control panel 40 of a portable size. Numeral 42designates a key switch for switching from an automatic operation modeto an inspection mode; numeral 43 designates an indicator lamp whichlights during operation; and 44 designates a push-button switch foremergency stop.

The control panel 40 and the control unit 36 are electrically connectedto each other by a cord 45 of a suitable length. The cord 45 can bedrawn out from a cord hole 46 within the recessed portion 41 as thecontrol panel 40 is removed from the recessed portion 41. Therefore,when the control panel 40 is received in the recessed portion 41, thecord 45 must be inserted into the cord hole 46. For this purpose,provision of an automatic winding device in the interior of the console39 affords easy insertion of the cord 45. Of course, it is possible toemploy a cordless (wireless) type control panel which can transmit acontrol signal to the control unit 36 through utilization of supersonicwaves or light rays.

The control panel 40 is provided with control buttons 47a, 47b formoving the traveling crane fore and aft, control buttons 48a, 48b formoving the lift carriage 6 upward and downward, and control buttons 49a,49b for advancing the transfer means 5 toward the fences 2, 3. Aninterlock release switch 51 is provided on a side of the control panel40 which is hidden from sight when the control panel 40 is received intothe recessed portion 41 of the console 39.

The control unit 36 controls individual drive units correspondingly inresponse to the operation of individual control buttons 47a through 49bon the control panel 40. This control unit 36 has an interlock functionwhich prohibits the control of the drive unit 37 for crane movement bythe run control buttons 47a, 47b unless interlock is released by aninterlock release switch 51. Therefore, in order to control the driveunit 37 by the control buttons 47a, 47b, the interlock release switch 51must be operated to release the interlock. The key switch 42 is operatedfor switching by a relevant key of the main switch used in the maincontrol board 15 on the ground side as shown in FIGS. 1 and 2.Therefore, it is impossible to control operation of the traveling crane1 by both the main control board 15 on the ground side and the controlpanel 40 at same time.

As the flow chart of FIG. 7 shows, when the key switch 42 is switchedfrom automatic operation mode to inspection mode by a relevant key, theup-and-down drive circuit and the drive circuit for the transfer means 8are both actuated. Accordingly, as FIG. 4 illustrates, an operator OPpresent on the ground right after the control unit 36 of the travelingcrane 1 operates control buttons 48a through 49b of the control panel 40to control the up-and-down drive unit 38 and the drive unit for thetransfer means 5 as desired, whereby the lift carriage 6 and thetransfer means 5 can be driven as required.

Where it is necessary to move the traveling crane 1, as FIG. 5 shows,the control panel 40 is removed from the console 39 and, with thecontrol panel 40 held in hand at a location which is a safety distanceaway from the crane 1, the interlock release switch 51 is operated torelease the interlock. As a result, the drive circuit 37 for crane runis actuated as FIG. 7 illustrates, and accordingly it is possible tocontrol the drive circuit 37 by control buttons 47a, 47b to move thecrane 1 in the desired direction, fore or aft. In this case, needless tosay, the crane 1 can be moved at a low speed only. With the controlpanel 40 removed from position to move the crane 1 in this way, the liftcarriage 6 and the transfer 5 can be driven into movement by operatingthe control buttons 48a to 49b.

Upon completion of the required operation, the interlock release switch51 is reset to its initial position at which the interlock mechanismfunctions, and then the control panel 40 is inserted into the recessedportion 41 of the console 39.

For the interlock release switch 51, a switch of the type which canautomatically reset to its initial position upon release of the fingermanipulating the switch 51 may be used. This saves the trouble ofresetting the interlock release switch 51 to its initial position. It isalso possible to provide a circuit arrangement such that interlock isreleased by one operation of the interlock release switch 51, while theinterlock mechanism functions automatically when the key switch 42 isswitched back to the automatic operation mode.

The traveling crane 1 can be automatically operated under presetconditions at the ground-side main control board by removing the key ofthe key switch 42 after switched to automatic operation mode and usingthe key to set the main key switch of the ground side main control boardto automatic operation mode.

A further embodiment of the invention is shown in FIGS. 8 to 11.

As FIGS. 3 and 6 show, the main control board 15 and the console 39 ofthe control unit 36 for the crane 1 are provided respectively with thenormally closed switch 25 for emergency stop and the push-button switch44 for emergency stop. If an emergency should occur during operation ofthe crane 1, the operator can operate the emergency switches 25, 44.

For purposes of maintenance and inspection, an operator may enter thenarrow travel path 4 for the crane. In such a case, the emergency stopswitches 25, 44 must be operated prior to his entry. However, if anotheroperator enters the travel path 4 at the opposite side of that side ofthe crane 1 at which is located the control unit 36 for manual craneoperation, it is very difficult for the operator to operate theemergency stop switch 44 on the console 39, and it takes time to do so.The operator who is in a position to control the console of the controlunit 36 for manual operation has difficulty in finding the presence ofanother operator in the travel path 4 at the opposite side of that sideof the crane 1 at which is located the control unit 36 for manualoperation, and may possibly operate the crane 1 without recognizing thepresence of the other operator in the direction of movement of thecrane 1. This involves a serious danger.

In view of such a possibility, the embodiment shown in FIGS. 8 to 11 isintended to assure safety in case of emergency, if an operator ispresent in the travel path 4 at either side of the crane 1, fore or aft.

The safety arrangement for an automatic warehousing facility accordingto the embodiment will be described in detail. In FIGS. 8 and 9, aconsole for manual operation of control panel 39 similar to the oneshown in FIGS. 4 and 5 is provided at the home-position HP side end ofthe crane 1, the control panel 39 being provided with an emergency stopswitch 56. Numeral 57 designates a control box disposed at one end ofthe crane 1 which is opposite to the home-position side end, that is, atthe out-position 58 side end of the travel path 4. An inspection switch59 is attached to the control box 57.

Both the emergency stop switch 56 and the inspection switch 59 arepush-button switches commonly known as push-lock type push buttonswitches, such that, as shown in FIG. 10, when a push button 60 ispushed in, it is automatically locked as pushed in and, when the pushbutton 60 is rotated, the lock is released to allow the button 60 toreset. The switches 56, 59, as FIG. 11 shows, have normally closedcontacts 61, 62 which are opened when the button 60 is depressed, thecontacts 61, 62 being connected in series to an electromagnetic relay63. Contacts 64 which are closed upon magnetization of the relay 63 areprovided in a power circuit 66 of a control unit 65 of the control board15 having functions to drive the traveling crane 1 into movement, thelift carriage 6 into up-and-down movement, and the transfer means 5 intomovement.

According to the above arrangement, when the emergency stop switch 56and inspection switch 59 are not in operation, that is, the normallyclosed contacts 61, 62 remain closed, the electromagnetic relay 63 isexcited to close its contacts 64, and accordingly the power circuit 66of the control unit 65 is closed so that the control unit 65 is allowedto perform its function. Thus, the operator can operate individualcontrol switches of the control panel 39 for manual operation to actuatethe traveling crane 1 into movement, the lift carriage 6 intoup-and-down movement, and/or the transfer means 5 into movement asrequired.

In case that an emergency occurs during such manual operation of thecrane 1, the push-button 60 of the emergency stop switch 56 on thecontrol panel 39 is depressed into locked position thereby to switch thenormally closed contacts 61 into their open condition. As a result, theelectromagnetic relay 63 is demagnetized to open the contacts 64, andthe control unit 65 is disconnected from the power supply, so that thetraveling crane 1 is automatically caused to stop all its operations.When the operator enters the travel path 4 to perform an operation at alocation between the crane 1 and the home position HP, he can operatethe emergency stop switch 56 on the manual-operation purpose controlpanel 39 of the crane 1 as above mentioned to disable the crane 1 fromall its functions. Thus, greater safety can be assured.

When the operator enters the travel path 4 to perform an operation at alocation between the crane 1 and the out position 58, the push button 60of the inspection switch 59 on the out-position side control box 57 ofthe crane 1 is depressed to lock in position thereby to switch thenormally closed contacts 62 to their open position. Thus, in the sameway as in the case of the emergency stop switch 56 is operated, theelectromagnetic relay 63 is demagnetized to open the contacts 64, andthe control unit 65 is disconnected from power supply, with the resultthat the traveling crane 1 is disabled from all its functions.Therefore, any dangerous occurrence such that another operatorinadvertently operates the manual-operation purpose control panel 39 toadvance the crane 1 can be effectively avoided.

FIGS. 12 through 16 illustrate another embodiment of the invention.

Generally, a traveling crane for automatic warehousing is equipped witha ladder for enabling the operator to transfer himself onto the liftcarriage for emergency and/or maintenance and inspection purposes,though not shown with respect to the embodiments in FIGS. 1 through 11.In order to ensure safety of the operator who goes up and down theladder, it is desirable to use a safety device for protection againstfalling, in combination with the ladder. Such a safety device forprotection against falling comprises a guide rail and a safety ropeconnecting slider up-and-down movable engageable with the guide rail andadapted to automatically lock in position when a safety rope connectedto the guide rail is pulled downward. The operator and the slider areinterconnected by the safety rope.

In order to have such a safety device in combination with the ladder, itis necessary to attach a guide rail, as a safety means, to one supportfor the ladder. For this purpose, the combined strength of the laddersupport and guide rail must be sufficiently high to withstand any greatimpact that may be applied in the course of automatic locking. Further,the ladder support itself must have reasonably great strength. Thisrequires a large sized ladder, which leads to increased cost.

In view of this fact, the embodiment shown in FIGS. 12 to 16 is intendedto provide for reasonable reduction in size and weight of such a ladderequipped with safety means and yet to assure greater safety.

In FIGS. 12 through 16, numeral 71 designates an emergency ladderattached to the outer side of one support 35a of the crane 1. The ladder71 comprises a pair of supports 72a, 72b, and step members 73 disposedin equal intervals between the pair of supports 72a, 72b. Numeral 74designates an auxiliary ladder releasably locked to the lower end of theemergency ladder 71, which is removed when it is not needed. Numeral 75designates a transfer step attached to the lift carriage 61.

The one support 72a of the ladder 71 comprises a step member fixingportion 76 and a guide rail 77 formed integrally with the step memberfixing portion 76, the guide rail 77 having a T-shaped sectionalconfiguration. The step member fixing portion 76 is identical with theother support 72b in its entirety, and comprises a U-shaped grooveportion 78 to which one end of a step member 73 is fixedly fitted, and apair of parallel mounting U-shaped grooves 79, a series of such groovecombinations being formed over the entire length of the step memberfixing portion 76. The ladder 71 is mounted in position by coupling thetwo supports 72a, 72b to opposite ends of a U-shaped bracket 80 fixed tothe crane support 35a, by bolts 81 and nuts 82 in such a way that theheads of the bolts 81 are unrotatably received into the mountingU-shaped grooves.

A slider 83, a known-type safety device for protection against falling,is vertically movably fitted on the guide rail 77. The slider 83 isprovided with a safety rope connecting lever 85 to which is connected asafety rope 84. The safety rope connecting lever 85 catches the guiderail 77 as it is pulled downward, so that the slider 83 is locked to theguide rail 77.

When it is necessary that the operator should go up on the lift carriage6 and/or racks 2, 3 for maintenance and inspection purposes, theauxiliary ladder 74 is connected to the lower end of the emergencyladder 71 of the traveling crane 1 at a standstill. The operator canutilize the auxiliary ladder 74 and emergency ladder 71 to go up anddown between the lift carriage 6 and the ground. To go up and down theemergency ladder 71, the safety rope 84 connected to the slider 83should be locked to a safety belt secured to the operator's waist. Bydoing so, the operator can be prevented from falling by virtue of thesafety rope 84 and slider 84 in the event that he should miss hisfooting on the ladder stairs, because the safety rope 84 is tightlypulled downward so that the slider 83 is automatically locked to theguide rail 77.

What is claimed is:
 1. A safety arrangement for an automatic warehousingfacility equipped with a traveling crane adapted to carry out goodstake-in and take-out operations and movable along storage racks,comprising:a crane travel path extending along the racks, a safetyenclosure provided with an open/close door which is disposed at one endof the travel path, discriminator means which determines whether or notthe open/close door of the safety enclosure is in a closed condition,control means which prohibits the crane from moving when thediscriminator means has detected the open/close door is not in theclosed condition, wherein said safety enclosure further comprises safetyfence means disposed on both sides of the crane travel path and a cranecontrol board, and wherein said open/close door and crane control boardare placed in a row in front of the said one end of the travel path,connecting with said safety fence means on both sides of the path inU-shaped fashion.
 2. A safety arrangement for an automatic warehousingfacility as set forth in claim 1, wherein:said safety arrangementincludes incoming and outgoing goods-receiving means arranged outsidesaid safety fence means on both sides of said crane travel path, andsaid safety arrangement includes additional safety fence means outsidethe goods-receiving means on both sides of said crane travel path andextending in the direction of movement of said crane.